GE, F40/KBP/ECO-2, 2 Pack, This is a 40 watt, T12, Kitchen & Bath, linear fluorescent bulb, It has a medium bi-pin base. It's 48" long, and 1.5" in diameter. It has a 20,000 hour rated life, a CRI of 87, and a 3000 Kelvin (Warm White) color temperature.